An engine cooling structure has been known in which a water jacket through which cooling water flows is formed in a cylinder block that forms part of an engine, and a water jacket spacer for forming a passage for the cooling water is arranged in the water jacket. An example of this known engine cooling structure is disclosed in Patent Document 1.
In the engine cooling structure disclosed in Patent Document 1, a water jacket spacer which covers substantially the entirety of the outer periphery of cylinder liners is arranged in a water jacket, and a notch is cut in an upper portion of the water jacket spacer, thereby forming a space for increasing the flow rate of the cooling water that flows along the outer periphery of the cylinder liners. In this engine cooling structure, the cooling water is circulated along the inner and outer sides of the water jacket spacer.